RS52301B - PORTABLE ELECTRONIC INSTRUMENT FOR INJECTION OF LIQUID - Google Patents

Abstract

A drug delivery device comprising a housing (81), a door (88) which, in its open position, permits the insertion / removal of the drug container (83) into / from said housing (81), the door opening mechanism (89, 123, 125, 126, 82) for opening / closing said door (88), and a thrust member (84) that can be moved axially from its retracted position, located outside said drug container (83), to enter said container for drug (83) and pushes the liquid drug contained in said drug container (83) outside of said drug container (83) to deliver it to the patient, and then returns to its retracted position, comprising a mechanism for locking (94, 129) for automatically locking the door opening button (89) of the door opening mechanism (89, 123, 125, 126, 82) found, to prevent opening said door (88) when said thrust member (84) inside said drug container (83) and for automatic unlocking e of said door opening button (89) when said thrust member (84) is in its retracted position. The application contains 3 more patent claims.

Description

Technical field

The present invention relates to a drug delivery device, such as a hand-held, electronically controlled injection device for injectable liquid drugs, particularly of the type for performing subcutaneous injections in a fully automatic manner.

State of the art

As is known, certain types of diseases, such as diabetes, require drugs to be injected, such as insulin, several times a day, and the dose of drug to be injected may vary from patient to patient, and, for the same patient, throughout the day and from one day to the next.

Therefore, in recent years, electronically controlled injection devices have been developed and are widely used to allow self-injection of drugs in required doses.

Patent application US-A-2002/0133113 describes one such injection device which consists essentially of a hand-held housing, in which is placed a cartridge containing a liquid medicine to be injected, and defines, on the contact surface where it contacts the patient's skin, through an opening into which a disposable needle is placed at one end of the cartridge. The injection device also consists of an electromechanical actuator assembly, which is actuated selectively to move a switch by means of a switch rod that is hermetically sealed within the cartridge body and delivers liquid medication through a needle into the patient's skin.

The operation of the injection device is controlled by a programmable microprocessor, which receives signals from various switches and buttons - e.g. buttons for selecting one or more doses of the drug and a button for starting the injection - and which generates signals that control the drive train according to the program stored in the microprocessor.

The injection device described accordingly ensures that each dose of drug for injection is selected and delivers the dose automatically.

One of the known drawbacks of existing drug delivery devices is that if the user attempts to remove the cartridge while the switch rod is still in the cartridge, typically between two injections, this can cause damage.

DE 29 50 140 A1 describes a drug delivery device according to the preamble of claim 1, namely, a fully mechanical syringe with ampoule consisting of a cylindrical housing having valves which, in the open position, allow insertion of the ampoule into the housing. The valves are subject to the action of the rings which tend to keep them in the open position. The valves have extensions that are pushed by the ampulla during insertion of the latter, causing the valves to close. When the ampoule is in the housing, the axially movable part is moved by the action of the spring towards the front end of the syringe to push the ampoule and to fix the valves in the closed position. The valves can be unlocked by returning the valve piston so that the enlarged end of the valve piston rests on the surface of said movable part and returns the latter out of the housing. When in the open position, one of the flaps retains said movable part by means of its extensions.

Thus, with such a syringe, removal of the ampoule by the user while the valve plunger is still in the ampoule is prevented. However, such a syringe has the disadvantage that its valves remain open and that said moving part continuously exerts pressure on the extension of one of the valves when the ampoule is not inserted into the syringe.

Description of the invention

It is an object of the present invention to provide a drug delivery device that corrects the aforementioned deficiencies.

To this end, and as defined in claim 1, the present invention provides a drug delivery device comprising a housing, a door which, in its open position, allows the insertion/removal of a drug container into/from said housing, a door opening mechanism for opening/closing said door, and an axially movable thrust member from a retracted position, located outside said drug container, to introduce said drug container and push out the liquid drug to be contained in said drug container outside the drug container to be delivered to the patient, and then returned to its retracted position, characterized by comprising a locking mechanism for locking the door of the door opening button of said door opening mechanism, to prevent said door from being opened, when said pushing member is inside said drug container and for unlocking said door opening button when said pushing member is in its retracted position.

Short description of the pictures

An assumed, non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a front view of a first exemplary injection device; Figures 2 and 3 show, with parts removed for clarity, enlarged perspective view, from opposite sides of the internal components

injection device from Figure 1;

Figures 4, 5, 6 and 7 show part of the injection device of Figure 1 which they illustrate

disposable needle assembly;

Figures 9, 10 and 11 are similar to Figures 4-8, and illustrate removal of the needle from the device

injection of Figure 1;

Figure 12 shows a block diagram illustrating the operation of the control unit for

controlling the injection device of Figure 1;

Figures 13 and 14 are front views of another exemplary injection device,

with the front wall removed to reveal the inside of the device;

Figures 15 and 16 are cross-sectional views of the interior of another exemplary injection device, showing various positions of the member for

device suppression;

Figures 17 and 18 are cross-sectional views showing the needle and end of the cartridge inserted into another exemplary injection device, each separately in

in the unfolded state;

Figures 19 to 22 are cross-sections showing the needle connection process

for the cartridge;

Figures 23 to 25 are cross-sections showing the process of separating the needle from

cartridges;

Figures 26 through 29 show the interior of another exemplary injection device, including sensing means

recognition of cartridge needle connections;

Figures 30 and 31 show alternative sensing means for recognition

cartridge needle connections;

Figures 32 through 34 are each separately a front view, a side view, and a partially reduced side view with parts removed for clarity, of parts of another exemplary injection device including a door opening mechanism and a door opening mechanism.

locking the door according to the invention in the first configuration;

Figures 35 through 37 are each separately a front view, a side view, and a partially reduced side view with parts removed for clarity, of parts of another exemplary injection device including a door opening mechanism and a door opening mechanism.

locking the door according to the invention in another configuration;

Figures 38 through 40 are each separately a front view, a side view, and a partially reduced side view with parts removed for clarity, of a portion of another exemplary injection device.

including the mechanism for opening the door and the mechanism for

locking the door according to the invention in a third configuration; Figure 41 is a block diagram illustrating the operation of the radio control unit

controlling another exemplary injection device.

The best way to carry out the invention

Numeral 1 in Figure 1 indicates an entirely manual, electronically controlled injection device for injecting liquid drugs, and in particular for performing subcutaneous injections fully automatically.

The injection device 1 essentially consists of a hand-held housing 2 that defines a bed 3 to receive a cartridge 4 containing a liquid medicine; the injection delivery unit 5 (Figures 2 and 3) located inside the housing 2 and which is selectively activated to cooperate with the cartridge 4 and inject the patient with a previously determined dose of the drug; and electronic control units 6 (Figure 12) - in the example given; microprocessor - which can also be placed inside the housing 2 to control the operation of the injection unit 5.

More specifically, the housing 2, in the given example, is of a thin prismatic shape, and consists of a front wall 7 equipped with an LCD screen 8 and adjustment buttons 9 (whose operation will be described in more detail later); rear wall 10; two pages 11, 12; the lower wall 15 which defines the contact surface 16 in order to make contact with the patient's skin; and an upper wall 17 which is equipped with an injection start button 18, as will be explained in more detail below.

As shown in Figure 1, one of the sides (11) of the housing 2 has a door 19 hinged at the bottom about an axis vertical to the front wall 7 and the rear wall 10, and which opens outwards to allow the insertion of the cartridge 4 inside the seat 3.

In the given example, the seat 3 for receiving the cartridge 4 has an axis A vertical with respect to the lower wall 15 and the upper wall 17, and is formed close to the side 11.

Near the opposite wall 13, the housing also defines a seat 20 (Figures 1 to 3) which has an axis parallel to the axis A, and for receiving one or more batteries 21 for powering the injection device 1, and which are inserted through the next door 22 formed in the lower wall 15.

As shown in Figures 1 to 11, the cartridge 4 is defined by a hollow cylindrical body 23 which contains a predetermined amount of liquid medicine, and which has a closed, small end part 23, through which a common disposable needle existing on the market can be inserted in a known manner, and an open opposite end 26 which is included in a way that makes the fluid tight through a disc-shaped member or piston 27, which is actuated by the injection delivery unit 5 to slides inside the body 23 and delivers the drug through the needle 25.

The cartridge is inserted inside the housing 2 with the end 24 for the needle 25 facing the bottom wall 15 and, therefore, in contact with the surface 16 for contacting the patient's skin; and the lower wall 15 has a passage through the opening 30, shaft A, by which the needle 25 is fitted and removed from the cartridge 4, and through which the needle 25 is ejected to perform the injection through the skin.

The cartridge 4 has known external signs (not shown), e.g., barcodes, notches, working or reflective material according to a predetermined pattern, etc., which determine the presence of the cartridge 4 inside the housing 2, and to obtain information related to the drug, such as composition, concentration, expiration date for use, etc. The next possibility to identify cartridge 4 is to use a radio frequency identification system.

As clearly shown in Figures 4 through 6, the needle 25 is housed in a protective needle housing 31 to prevent injury to the user, and defines, with the needle housing 31, a needle assembly 32.

More specifically, the needle 25 is fixed to and projects from the plastic needle support 33 which fits into the rear end 24 of the body 23 of the cartridge 4.

As is known, the needle 25 consists of a front part 34 (bottom of Figs. 2 to 11) for piercing the patient's skin and projecting from the needle support 33, and a back part 35 (top in Figs. 4 to 11) enclosed in the needle support 33 and fitting through the end 24 of the body 23 of the cartridge 4. More specifically, the needle support 33 consists of a number of elastic edges 36 which surround the rear end 35 of the needle 25, and which engage the end 24 of the body 23 of the cartridge 4 as described in detail below.

As an alternative not shown, the opposite arrangement of engagement between the pin support and the end of the cartridge is possible; in this latter case, the end of the cartridge may be provided with elastic edges which engage the supporting needle. This further embodiment has the advantage that the needle support does not have to be specially designed with elastic edges, but standard commercially available assemblies can be used (even threaded ones, which are a common commercially available version).

The needle housing 31 is defined by a cylindrical, dome-shaped housing body of the front part 34 of the needle 25, and an open end that fits into the support of the needle 33. In the example shown, the needle assembly 32 also consists of an inner needle housing 37 that covers the front part 34 of the needle 25.

With reference to Figures 2 and 3, the injection delivery unit 5 consists of an electromechanical actuator assembly 40, which is selectively actuated to act as the piston 27 of the cartridge 4 and to move it, within the body 23 of the cartridge 4, towards the end 24 to deliver the liquid medication through the needle 25.

The injection delivery unit 5 consists of another electromechanical actuator assembly 41 to move the cartridge 4, inside the housing 2 along the axis A, to and from the contact surface 16 to automatically fit and remove the needle 25 to/from the cartridge 4, and to insert the needle 25 into the patient's skin at a predetermined speed.

More specifically, the cartridge 4 fits into the support sleeve 42 which slides axially within the seat 3 of the housing 2.

As shown in Figures 2 and 3, the support sleeve 42 is open, not only at the lower axial ends, but also on the side facing the door 19 to allow the insertion of the cartridge 4.

More specifically, the support sleeve 42 consists of a small part of the lower end 38 for receiving the end 24 of the cartridge 4, and which, when fitting the needle 25 for the partron 4, is engaged by the elastic edges 36 of the support of the needle 33. The end part 38 also defines an annular shoulder 39 with a support for the support sleeve 42.

The actuator assembly 40 consists of an electric drive motor 43; a pushing member 44 which acts on the piston 27 of the cartridge 4 to move it, inside the body 23 of the cartridge 4, towards the end 24; and the transmission 45 to convert the rotation generated by the drive motor 43 into translation of the pushing member 44.

More specifically (Figure 2), the transmission 45 essentially consists of a gear 46 that fits into the output member of the drive motor 43; thread assembly 47 connected to pusher member 44; and an intermediate gear 48 having external teeth meshing with the gear 46 and internal teeth engaging the main thread 49 of the thread assembly 47.

More specifically, the main thread 49 fits into the housing 2 in order to rotate but not transmit axially; and the thread assembly 47 also consists of a threaded nut 50 which fits into the main thread 49 , integral with the thrust member, and fits into the housing 2 to be transmitted longitudinally but not rotated relative to the main thread 49 .

The pushing member 44 is advantageously defined with a core of a known flexible Bowden-type cable 51, a sheath 52 of which a portion is fixed to the housing 2, e.g., the top wall 17.

The actuator assembly 41 consists of an electric drive motor 53; the slide 54 as an integral part with the support sleeve 42 of the cartridge 4 which can be moved parallel to the axis A; and the transmission 55 for converting the rotation generated by the drive motor 53 into transmission to the slider 54.

More specifically (Figure 3), the slider 54 is defined by a threaded nut that projects laterally (sideways) from the support sleeve 42 and fits into the housing 2 to be transmitted longitudinally, but not to rotate with respect to an axis parallel to the axis A. The transmission 55 consists of a gear 56 that fits the output member of the drive motor 53; the main screw 57 which is connected to the slide 54 and fits into the housing 2 to rotate about, but not to transmit along, its own axis; and an intermediate gear 58 having external teeth meshing with the gear 56 and internal teeth engaging the main thread 57.

Referring to Figures 4 to 11, the injection device 1 also comprises two or more retaining members 60 extending around the seat 3 to hold the needle assembly 32 fitted in the housing 2 in a predetermined position (Figure 5), where the needle assembly 32 projects along the axis A from the bottom wall 15 of the housing 2 and the needle support portion 33 engages the opening 39 in the wall 15.

More specifically, the retaining elements 60 are defined with levers extending parallel to the axis A and having upper ends 51 hinged to the structural part of the housing 2, and free lower ends having locking edges 62. More specifically, the locking edges 62 are located on the opening 30, and extend vertically to the axis A and inside the opening 30.

The retaining elements 60 are loaded elastically within the seat 3 to assume a locking configuration (Figures 5, 6, 10 and 11), and are tracked in a release configuration (Figures 4, 7, 8 and 9) each with a special cam profile 63 that interacts with a strong annular projection 64 on the support sleeve 42, as the support sleeve 42 moves. along the A axis.

More specifically, the support sleeve 42 and, with it, the cartridge 4 can be moved together by the actuator assembly 41 in different directions along the axis A to assume three specific positions, namely: - The upper end position (Figures 4 and 7) in which the cartridge 4 is loaded and each automatic operation of the injection device 1 (in this case, the assembly and removal of the needle 25, and the injection of the drug to the patient) begins and ends its operation; - Lower end position (Figures 10 and 11) in which the needle 25 is removed from the cartridge 4; and - Working position (Figure 6), close to the lower end position, in which the liquid drug is delivered through the patient's skin, and the needle 25 is connected to the cartridge 4.

As shown in Figures 4 to 11, the cam profile 53 of each retaining member 60 and the projection 64 on the support sleeve 42 are in the form of complementary platforms and are designed to work together to follow the retaining members 60 in and near the upper end position of the supporting sleeve 42, and to separate from each other, leaving the retaining members 60 subject only to an elastic force of return to the axis A, in other positions taken over by the support sleeve 42 during its movement.

As shown in Figures 5 and 6, in the latched configuration, the latching edges 62 of the retaining members 60 work together with the outer rib 65 formed on the open end of the needle housing 31 to retain the needle assembly 32 within the opening 30 in the lower wall 15 as the support sleeve 42 moves into the operating position so that the end portion 38 of the support sleeve 42 is fitted within the elastic the support edge of the needle 33, and the rear part 35 of the needle 25 is inserted inside the end 24 of the cartridge 4.

As the support sleeve 42 then moves from the operating position toward the upper end position, the locking edges 62 of the retaining members 60, still in the locked configuration, press the needle housing 31 to prevent it from following the needle 25, the needle support 33 and the inner needle housing 37 move together with the support sleeve 42 so that the needle 25 and the needle support 33 are connected to cartridge 4 and return from the needle housing 31 automatically.

It can be noted that the retention members 60, as they press against the needle housing 31, lock the needle housing 31 towards the user as well. Thus, untimely removal of the needle housing 31 by the user, e.g. since pin 25 is connected to cartridge 4.

In the lower end position of the support sleeve 42 (Figures 10 and 11), the locking edges 62 of the retaining elements 60 engage the space between the shoulder 39 of the support sleeve 42 and the rear part of the needle support 33 to stop the needle support 33 as the support sleeve 42 then moves to the upper end position, so that the needle 25 and the needle support 33 are withdrawn automatically from the cartridge 4 after use.

With reference to Figure 12, the control unit 6 receives a number of signals from various detecting elements and buttons on the injection device 1, and supplies control signals to the drive motors 43, 53 and the display 8, in accordance with the program stored in the control unit 6 itself.

More specifically, the control unit 6 receives the following signals:

- Signals S1 from the sensor 55 (eg optical, electrical, radio-frequency, infrared, etc.) directed to the seat 3 and for the purpose of detecting the markings on the cartridge 4; - Signal S2 from presence sensor 67, e.g. contact switch, located on the opening 30 in the lower wall 15 and in order to determine the engagement of the opening by an external body of a previously determined diameter, e.g. needle housing 31; - Signal S3 from skin sensor 68, e.g. a mechanical or capacitive sensor, mounted on the lower wall 15 of the housing 2a to determine the contact with the patient's skin; - Signals S4 from adjustment buttons 9, which select, for example, the dose to be injected, the speed with which the needle 25 penetrates the patient's skin, the speed of drug delivery, etc.; and

- Signal S5 from the start button injected 18.

Based on the incoming signals, the control unit 6 supplies signals C1 and C2 to control each drive motor 43, 53 in both directions of rotation, and signal C3 to control the screen 8.

The control unit 6 has its own internal memory 70 (shown externally for simplicity) which stores the operating program of the control unit 6 and the doses as well as the time of injections performed, in order to inform the patient and/or the doctor about this and the number of doses remaining in the cartridge 4. The doctor can therefore check the acceptance of the therapy by the patient.

Injector 1 is also given with an interface (known by itself so not shown) e.g. USB port, Bluetooth communication, infrared port, etc., which allows the exchange of information with a computer for data analysis.

Programming of the injection device 1 may also be possible (for example by uploading from a computer), which may be useful for clinical trials (for example, allowing the injection of only certain amounts at certain time intervals).

The operation of the injection device 1 will be described with the configuration of Figure 4, where the support sleeve 42 does not have the pin 25 and is placed in the upper end position, and the cartridge 4 is inserted through the door 19 into the seat 3 of the housing 2 and connected to the support sleeve 42.

The coupling of the needle 25 to the cartridge 4 is controlled fully automatically by the control unit 6, and is activated simply by inserting the needle assembly 32, open at the end of the needle housing 31, into the hole 30 in the bottom wall 15 of the housing 2. The insertion of the needle assembly is instantly detected by the presence sensor 67, so that the control unit 6 activates the drive motor 53 in the direction designed, via the transmission 55 and the slide 54, to moves the support sleeve 42 into the working position.

As a result of the upward movement of the support sleeve 42, the projection 64 is separated from the cam profiles 63, so that the retaining elements 60 move inside the opening 30, and the locking edges 62 close on the housing of the pin 31 to lock it in a position that partially engages the opening 30 (Figure 5).

The pin assembly 32 may be inserted into the opening 30 either by hand or by using an adapter indicated generally at 71 in Figures 4 through 10.

More specifically, the adapter 71 is in the form of a double cup, and consists of opposite parts 72, 73 of different diameters which define each cavity opening on opposite sides as well as to accommodate the needle housing 31 and the inner needle housing 37 each separately. The larger section of the part 72 also accommodates the cylindrical sliding sleeve 76 which defines the actual seat for the needle housing 31, and whose function is explained below; and a smaller section of the portion 73 is provided internally, near the open end, with an internal rib 74 which presses the inside of the needle housing 37 to be removed from the assembly defined by the needle-35 and the needle support 33.

When the support sleeve 42 reaches the working position (Figure 6), the end part 38 is inserted between the elastic edges 36 and tied to the support of the needle 33, and the rear end 35 of the needle 25 is inserted inside the end 24 of the cartridge 4.

At this point, the direction of rotation of the drive motor 53 is reversed, and the support sleeve 42 moves from the working position to the upper end position. As it does so, the needle support 33, the needle 25 and, with them, the inner needle housing 37 are withdrawn axially from the needle housing 31 partially locked by engaging the opening 30 with the retaining members 60.

Near the upper end position, the projection 64 on the support sleeve 42 interacts with the cam profiles 63 of the retaining elements 60 toward the retaining element portion, so that the locking edges 62 move out of the opening 30 to release the needle housing 31 (Figure 7).

Once the support sleeve reaches the upper end position, the adapter 71 can be inserted through the opening 39 into the seat 3 by the part 73, the cavity of which is thus engaged by the inner housing of the needle 37. Since it is of a smaller diameter, the insertion of the end 73 is not detected by the presence sensor 67. When the adapter 71 is removed from the opening 30, the inner housing of the needle 37 is removed from the needle 25 (Figure 8).

Consent to start the actual injection is given via the surface 16 which contacts the patient's skin and thus activates the skin sensor 68.

When the start button 18 is pressed, the drive motor 53 is first activated, via the transmission 55, it moves the support sleeve 42 back to the working position, so that the needle 25 penetrates the patient's skin. The drive motor 43 is then activated and, via the transmission 45 and the pushing member 44, acts on the piston 27 of the cartridge 4 to slide it towards the end 24 and deliver the predetermined dose of liquid medication.

Before the injection is performed, the dose to be injected, the speed at which the needle 25 penetrates the patient's skin, the speed at which the liquid drug is delivered and the depth of injection can be selected using the adjustment buttons 9 and displayed on the screen 8.

After the injection is done, the support arm is moved back to the upper end position.

The needle 25 can be removed from the cartridge 4 fully automatically using the adapter 71 (Figures 9 and 10), or directly using the needle box 75 (Figure 11), e.g. of the type known under the trade name "SHARPS BOX".

More specifically, when using the adapter 71 to remove the needle housing 31 and the inner needle housing 37 (Figures 9 and 10), the sliding sleeve 76 must first be removed from the portion 72 to rest axially on the rib 65 of the needle housing 31.

At this point, the needle housing 31 and the extended part of the sliding sleeve 76 are inserted through the opening 30 into the housing 2 to activate the presence sensor 67, so that the control unit 6 activates the drive motor 53 to move the support sleeve 42 from the upper end position to the lower end position.

The cam profiles are separated from the projection 64 on the support sleeve 42, the retaining elements 60 are prevented from moving into the locked configuration by the locking edges 62 which rest on the sliding sleeve 76 of the adapter 71 (Figure 9).

When the support sleeve 42 reaches the lower end position (Figure 10), however, the locking edges 62 of the retaining elements 60 fall within the space between the shoulder 39 of the support sleeve 42 and the upper axial end of the needle support 33.

At this point, the direction of rotation of the drive motor 53 is reversed, and the support sleeve 42 is moved to the upper end position. Having done so, the needle support 33 and the needle 25 remain in the position in which they are held by the locking edges 62, and are thus withdrawn axially from the support sleeve 42 and the cartridge 4.

When the support sleeve 42 reaches the upper end position, the retaining elements 60 are separated again, and the injection device 1 is ready to be fitted with the second needle 25 for the next injection.

When using the needle box 75 (Figure 11) it is simply inserted into the mouth inside the opening 30 to activate the presence sensor 67 and automatically remove the needle 25 from the cartridge 4 in exactly the same way as described in relation to the adapter 71.

The advantages of the injection device 1 will be clear from the following description.

In particular, by allowing control of the movement of the cartridge 4 to and from the contact surface 16, the injection device 1 provides fully automated fitting and removal of the needle 25 to/from the cartridge 4, and controls the rate at which the needle 25 will penetrate the patient's skin.

In other words, when the actual injection is performed, it is possible to adjust not only the dose of the drug and the rate at which the dose is delivered, but also the rate at which the needle 25 is ejected from the housing 2, and therefore the rate of penetration through the skin.

It is clear that changes can be made to the injection device 1 as described and illustrated herein.

In particular, the movement of the cartridge 4 and the delivery of the drug contained in the cartridge 4 can be controlled by the use of a single drive motor, which can, for example, by means of a transmission similar to that described, control the axial removal of the core of the flexible Bowden-type cable on the piston 27 of the cartridge 4; and releasable locking means may be provided to selectively make the plunger 27 and the body 23 of the cartridge 4 integral with each other so that, when the locking means are activated, the cartridge 4 moves away from and toward the contact surface 16, and, when the locking means is released, the plunger 27 slides within the body 23 of the cartridge 4 to deliver the drug.

1

Further, the injection device 1 can be used, in the same manner as disclosed herein, with any other types of drug container, such as a syringe.

Figures 13-16 show a hand-held, electronically controlled injection device 80. Like the injection device 1, the injection device 80 shown in Figures 13-16 consists of, within a housing 81 (shown only in Figures 13, 14), a cartridge holder 82 for housing a cartridge 83 containing liquid medication, a pusher member 84 designed to act as a piston 85 of the cartridge 83, a first valve an electromechanical actuator 86 for driving the pusher member 84 and another electromechanical actuator assembly 87 for axially moving, in particular, the cartridge holder 82. A door 88 provided on the side wall of the housing 81, and actuated by a sliding button 89 provided on the same side wall, can be opened by rotating about the axis of rotation 90 to insert or remove the cartridge 83 into/from the injection device. The cartridge holder 82 is axially movable relative to the door 88 but is rotatable with the door 88 about the axis of rotation 90 when in the axially retracted position.

The pushing member 84 consists of an axially incompressible laterally flexible tube 91 having the shape of a spring, and is deflected 180° by guiding a rigid semicircular housing 92 to the upper part of the device, and a piston 93 fixed to the end of the tube 91 projects from the housing 92 along the axis B of the cartridge holder 82 and the cartridge 83. The piston 93 is designed to work together with the piston 85 of the cartridge 83 (see Figure 16) as well as with the movable recessed part 94 (see Figure 15) whose function will be explained later.

Under the control of the control unit 95, shown in Fig. 41, the first actuator assembly 86 can move the pushing member 84 axially from the retracted position, in which the piston 93 is outside the cartridge 83 and within the recessed portion 94 (Fig. 15) towards the disposable needle 96 connected to the cartridge 83, so that the piston 93 contacts the piston 85 to deliver the drug through the needle 96 (Fig. 16). The pushing member 84 can then be moved back to its retracted position, leaving the piston 85 in the pushed position.

The second actuator assembly 87 can be controlled by the control unit 95 to move the structure consisting of the first actuator assembly 86, the pushing member 84, the housing 92 of the pushing member and the cartridge holder 82 along the axis B, that is, to and from the bottom wall 97 of the device housing 81 for contact with the patient's skin, to automatically fit and remove the needle 96 to/from the cartridge 83 and to insert or remove the needle 96 on/from the patient's skin. More specifically, the structure 82, 84, 86, 92 can be moved between an upper, retracted position in which the needle 96 is connected to the cartridge 83 within the device housing 81, and one or more lower positions in which the needle 96 projects from a passage opening 98 provided in the lower wall 97.

Referring to Figures 17, 18, a needle 96 is fixed to and projects from a plastic needle support 99 which fits into the lower end 100 of the cartridge holder 82 so that the corresponding lower end 83a of the cartridge 83, surrounded by the lower end 100, is pierced by the lower end 101 of the needle 96. The fitting of the needle support 99 to the cartridge holder 82 is achieved by means of an intermediate metal member. 102 fixed to the lower end 100 of the cartridge 82 which has a number of elastic edges 103 which can be compressed between the outer peripheral wall of the needle support 99 in the cuts 82a provided in the wall of the cartridge holder.

Before connecting the needle 96 to the cartridge 83, the needle support 99, with the needle 96, fits into the protective needle housing or needle cap 104 and forms with the bottom of the needle cap 105 (see Figures 19-20).

Referring to Figures 19-20, the injection device 80 further comprises releasable retention means for retaining the needle assembly 105 in a predetermined position within the opening 98 of the bottom wall 97. These releasable retention means consist of two or more releasable inserts or rings 105, which actuate the needle assembly 105 after its insertion into the opening 98, and an axial boundary surface. 107 that restricts insertion of the needle assembly 105 into the bore 98. Releasable retainer inserts 106 are exposed at the periphery of the bore 98 and are subjected to elastic loading directed toward axis B. With the boundary surface 107, the releasable retainer inserts 106 define gaps that are engaged by the annular upper flange 108 of the needle housing 104 to lock the needle assembly 105 in the opening 98. An electro-mechanical sensor (electrical switch) 109 (Figure 41), connected to the releasable retaining inserts 106, detects the actuation of the inserts 106 via the needle housing 105 and sends an electrical signal to the control unit 95.

The automatic connection of the needle 96 to the cartridge 83 is activated by the insertion of the needle assembly 105 between the inserts 106. This insertion, instantly detected by the sensor 109, causes the control unit 95 to activate another actuator assembly 87 to move down the structure 82, 84, 86, 92 within the device housing 81 from its retracted position. The retaining force exerted by the retaining insert 106 on the needle housing 104 is sufficient to keep the needle housing 104 painted in its position shown in Figure 20 while the lower end 100 of the cartridge holder 102 engages the needle support 99 (Figure 21). Once the movable structure 82, 84, 86, 92 reaches a predetermined lower position, in which the lower end 100 of the cartridge holder 82 fully engages the needle support 99, thus connecting the needle 96 to the cartridge 83, the second actuator assembly 87 moves the structure 82, 84, 86, 92 back towards its top, a retracted position is reached with the needle support 99 and the needle 96 connected to the cartridge 83 while the needle housing 104 is retained by the boundary surface 107 (Figure 22).

Unlike the retention elements 60 in the injection device 1, the retention inserts 106 do not prevent the user from removing the needle housing 104 during the connection of the needle 96 to the cartridge 83. However, any removal of the needle housing 104 during the connection process is detected by the sensor 109. If such removal occurs, the control unit 95 immediately stops the connection process and controls the return of the movable structure 82, 84, 86, 92 to its upper position. The user will then be prompted, via a screen display 110 (Figure 41) provided on the injection device, to initiate a new bonding procedure.

To remove the needle 96 from the cartridge 83, the user inserts the empty needle housing 104 into the opening 98 until the retention means 106, 107 are engaged by the needle housing 104. The actuating inserts 106 are detected by the sensor 107. This causes the control unit 95 to activate the second actuating assembly 87 to move the structure 82, 84, 86, 92 down towards the lower position where the needle support 99 is fitted into the needle housing 104 (Figures 23, 24). The user can then actuate the needle release button 111 provided on the device housing 81 and connected to the control unit 95, to move the square retaining member 112 transversely to the axis B to a position where the leg 113 of the retaining member 112 is inserted into the space between the boundary surface 107 and the annular upper flange 107 of the needle housing 104, above the upper end of the needle support 99 (Fig. 24). Thereafter, reverse movement is communicated to the structure 82, 84, 86, 92 while the needle support 99 and, with it, the needle 96 remain retained by the retention member 112, thereby separating the needle support 99 and the needle 96 from the cartridge holder 82 and the cartridge 83 (Figure 25). The user then releases the needle assembly 105 from the retention inserts 106 and removes them from the injection device.

Sensor means are provided in the injection device to detect the connection of the needle 96 to the cartridge 83. These sensor means, visible in Figures 26-29, consist of an optical transmitter 114, such as a light emitting diode, and first and second optical receivers 115, 116, such as photodiodes, fixed to the inner face of the front or rear wall of the device housing 81, and a reflector 117, such as mirror, fixed on the opposite front or rear wall of the device housing 81. The optical transmitter 114 is aligned with the first and second optical receivers 115, 116 in a line parallel to the axis B and is placed between them. When the cartridge holder 82, more precisely the movable structure 82, 84, 86, 92, is in the retracted position and the needle is not connected to the cartridge 83 (Figure 26), the first optical beam 118 forming part of the beam emitted by the transmitter 114 passes first near the lower end 100 of the cartridge holder 82, and is reflected by the mirror 117 and passes a second time near the lower end 100 of the cartridge holder 82 to reach the first receiver 115, and the second optical beam 119 transmitted by the transmitter 114 passes the first time near the lower end 100, and is reflected by the mirror 117 and passes the second time near the lower end 100 to reach the second receiver 116. As is evident in Figure 27, the cross section of the upper part of the lower end 100 of the holder cartridge 82 is only partially circular, that is, the lower end 100 has a hemmed, flat portion of the side 120 to allow the first optical beam 118 to pass. When the needle support 99, with the needle 96, is properly connected to the lower end 100 of the cartridge holder 82, the optical rays 118, 119 are interrupted by the needle support 99 (Figure 29). The receivers 115, 116 thus no longer receive the optical beams 118, 119. This is interpreted by the control unit 95 as indicating that the needle 96 is properly connected to the cartridge 83. Figure 28 shows an intermediate configuration where the needle support 99 and the needle 96 are only partially connected to the cartridge holder 82 and the cartridge 83. In this configuration, the second optical beam 119 is interrupted by of the needle support 99 but the first one, 118, still reaches the first receiver 115. This is interpreted by the control unit 95 as an indication that the needle 96 is only partially connected to the cartridge 83.

Thus, after the needle connection procedure described herein, if the control unit 95 determines that the needle is not connected to the cartridge 83 or that the needle is only partially connected to the cartridge 83, the user is not allowed to start the injection and is suggested to restart the needle connection procedure. The safety of using the injection device is thereby further increased.

Figures 30 and 31 show alternative sensor means for detecting the connection of the needle 96 to the cartridge 83. In this embodiment, one, 103a, of the elastic flanges 103 of the intermediate fixing member 102 is not larger than the other(s). When the cartridge holder 82 is in the retracted position and the needle 96 is properly connected to the cartridge 83, the longest elastic flange 103a, compressed between the needle support 99 and the lower end 83a of the cartridge 82, has an end portion that projects outside the needle support 99 and defines a first angle a1 with the axis B. In this configuration, the optical beam emitted by the optical transmitter 121 is is reflected by the projecting end part of the flange 103a towards the optical receiver 122. The reception of the signal by the optical receiver 122 is interpreted by the control unit 95 as an indication that the pin 96 is properly connected to the cartridge 83. If, on the other hand, the pin 96 is not properly connected to the cartridge 83, as shown in Figure 31, Then the projecting end part of the flange 103a defines another angle a2 different from the first angle ct1, with the axis B. In this case, the optical beam reflected by the projection of the end part of the flange 103a is not received by the receiver 122. This is interpreted by the control unit 95 as an indication that the needle is not connected to the cartridge 83 or that the needle is wrongly connected to the cartridge 83.

Returning to Figures 15 and 16, drug delivery through the needle 96 is, as explained above, accomplished by the plunger 93 of the pushing member 84 by cocking the plunger 85 of the cartridge 83. During this process, the plunger 93 and part of the tube 91 are in the cartridge 83. The plunger 93 and the tube 91 remain in the cartridge 83 as long as there is a dose of medication in it. Once all doses of the drug contained in the cartridge 83 have been injected into the patient, the pushing member is retracted out of the cartridge 83 to allow replacement of the latter (Figure 15). However, there is a risk that, between two injections, the user opens the door 88 to remove the cartridge 83 from the injection device while the pusher member 84 is still inside the cartridge 83. Such an operation can seriously damage the pusher member 84.

To eliminate this risk, the present invention advantageously provides a locking mechanism that locks/unlocks the door opening mechanism 88 when the pushing member 84 is inside/outside the cartridge 83 .

Referring to Figures 32-40, the door opening mechanism 88 is composed of an opening button 89, which can slide in a direction parallel to the axis B, a locking part 123 fixed to the opening button 89 inside the device housing 81 and having a flange 124, a lever 125 operated by the locking part 123, and a locking member 126 operated by the lever 125. The handle 125 is mounted on an axis fixed relative to the device housing 81. The locking member 126 is mounted on the movable structure 82, 84, 86, 92 at a location located on the opposite side of the axis B to the opening button 89 so that it can slide toward the movable structure 82, 84, 86, 92 in a line parallel to the axis B, and has a recess with flange 127 designed to work together with with the corresponding flange 128 of the cartridge holder 82.

The locking mechanism consists of a movable recessed part 94 and a lever 129 which is actuated by the recessed part 94 and has at one of its ends a flange 130 designed to cooperate with the flange 124 of the locking part 123. The lever is mounted on an axis which is fixed relative to the device housing 81. The recessed part 94 is movable along the axis B and fixed at one end springs 131 (visible in Figures 13-16) where the other end is fixed to the movable structure 82, 84, 86, 92.

The operation of the mechanisms for opening and closing is as follows: during the injection of a dose of varnish (Figures 32 - 34), the movable structure 82, 84, 86, 92 is in the lower position, the piston 93 of the pushing member 84 is inside the cartridge 83 and the recessed part 94 is in the position in which it does not work, without contact with the lever 129. In this configuration, the flange 130 of the second lever 129 engages the flange 124 of the locking part 123 (Figures 33, 34) so that the locking part 123 and, with it, the opening button 89 are locked, that is, they cannot be moved up, thus preventing the door 88 from being opened. Between two injections with the same cartridge 83, the movable structure 82, 84, 86, 92 is in the retracted position, the piston 93 of the pushing member 84 is inside the cartridge 83 and the recessed part 94 is in the position in which it is not engaged, without contact with the lever 129 (Figures 35-37). In this configuration, the flange 130 of the second lever 129 still engages the flange 124 of the locking portion 123 (Figure 37) so that the locking portion 123 and, with it, the opening button 89 remain locked, thus preventing the door 88 from being opened. Once all the drug doses contained in the cartridge 83 have been injected, the movable structure 82, 84, 86, 92 and the piston 93 of the pushing member 84 are each retracted. During retraction of the pushing member 84, the piston 93 enters the recess of the recessed portion 94 and pushes the recessed portion 94 onto the auger against the work of the spring 131 so that the recessed portion 94 contacts the end of the second lever 129 opposite the flanged end 124 to rotate the lever 129 and thus release it from the locking portion 123 (Figure 40). The door opening button 89 can then slide on the bark as shown in Figure 38. The upward movement of the opening button 89 causes the first lever 125 to rotate to move the locking member 126 down and thus release the flange 128 of the cartridge holder 82 from the flange 127 of the locking mechanism 126. Under the action of the spring, the door 88 and, with it, the cartridge holder 82 they then rotate about a circular axis 90 to allow the cartridge 83 to be ejected from the cartridge holder 82 (Figure 38). The door release button 89, lever 125, locking member 126 and lever 129 are each subjected to the action of an individual spring which tends to maintain it in the rest position shown in Figures 32 to 34 or 35 to 37.

Claims (4)

1. A drug delivery device comprising a housing (81), a door (88) which, in its open position, allows the insertion/removal of a drug container (83) into/from said housing (81), a door opening mechanism (89, 123, 125, 126, 82) to open/close said door (88), and a push member (84) which can be moved axially from its retracted position, located outside said drug container (83), to enter said drug container (83) and push the liquid drug contained in said drug container (83) out of said drug container (83) to deliver it to the patient, and then return to its retracted position, indicated by comprising a locking mechanism (94, 129) for automatically locking the door opening button (89) found in the door opening mechanism (89, 123, 125, 126, 82), to prevent said door (88) from opening when said pushing member (84) is inside said drug container (83) and to automatically unlock said door opening button (89) when said pushing member (84) is in its retracted position. 2. Device according to claim 1, characterized in that said locking mechanism (94, 129) consists of a first lever (129) which, in a rest position, locks said door opening button (89) and which is actuated by said pushing member (84) during the latter's withdrawal to unlock said door opening button (89). 3. Device according to claim 2, characterized in that the said locking mechanism (94, 129) further consists of a part (94) movable in the right of removal of the said pushing member (84) and which, in the rest position, is without contact with the said first lever (129) and, during the retraction of the said pushing member (84), is pushed by the end part (93) of the said pushing member (84) to come into contact with and actuate said first lever (129). 4. Device according to any one of claims 1 to 3, characterized in that said door opening button (89) is movable in the direction of removing said pushing member (84), and in that said door opening mechanism (89, 123, 125, 126, 82) consists of a second handle (125) which is actuated by said door opening button (89), a locking member (126) movable in said direction, actuated by said second lever (125) and having a first flange (127), and a drug container holder (83) within said housing (81), said drug container holder (82) having a second flange (128) designed to cooperate with said first flange (127) and rotatable with said door (88) when said second flange (128) is released by said first with the flange (127).